1. Field of the Invention
The present invention relates to conveying apparatus and, more particularly, is directed to advanceable auxiliary conveying apparatus for use in connection with mobile conveyor trains for conveying mined ore from a continuous mining machine.
2. Description of the Invention Background
In mining operations, especially in the underground mining of coal and the like, a variety of conveyors are used to transport the mined materials from the mining machine to their ultimate transportation location. During the early stages of mine development, main haulageways are created within the mine to accommodate stationary main belt conveyors that ultimately transport the mined ore from the mine or to remote collection areas. A variety of different conveying systems and apparatuses have been developed for transferring the mined material from the mining machine to the main belt conveyors.
One type of conveying apparatus commonly used to convey mined material from the mining machine to a main conveyor is a mobile articulated conveyor. Mobile articulated conveyors, such as the one disclosed in U.S. Pat. No. 4,852,724 to Bodimer, can move under self-propulsion along mine roadways and around corners while receiving the mined ore directly from the mining machine and discharging it onto the main conveyor or onto a separate stationary "panel" conveyor arranged for discharge onto the main conveyor.
A number of different auxiliary conveying apparatuses exist for transferring the mined material from the discharge of the mobile articulated conveyor to a stationary panel conveyor or main conveyor. For example, in one conveyor arrangement, the discharge end of the mobile conveyor is arranged to tram beside the stationary main or panel conveyor and a third "bridge" conveyor is employed to transfer the mined ore from the mobile conveyor to the stationary conveyor. To enable the discharge end of the bridge conveyor to traverse between intersecting stationary conveyors without interrupting the mining process, additional conveyors and guiding apparatus are typically used.
In another conveyor arrangement, the mobile articulated conveyor is trammed onto an elevated roadway that is mounted above an attending stationary panel or main conveyor belt for discharge thereupon. Because this conveyor arrangement eliminates the need for a bridge conveyor and its accompanying conveying apparatus, it is typically the preferred practice in mining schemes having adequate overhead clearance to support such stacked arrangement of conveyors. However, to extend the conveying system, the mining process must be interrupted so that additional lengths of conveyor and elevated roadway can be added to the existing conveyor network.
One type of elevated discharge system that is particularly directed to minimizing the amount of time required to extend an elevated roadway and its accompanying conveying system is disclosed in U.S. Pat. No. 4,969,691 to Moore et al. That system comprises a floor mounted beltway that has an elevated roadway rollably attached thereto. The beltway comprises a series of interconnected frame units that rest on the mine floor and support a continuous conveyor belt. The elevated roadway has wheels that are captured in outboard rails attached to the beltway for movably supporting the roadway thereon. Lift cylinders are attached to the roadway for lifting the beltway from the mine floor so that the beltway can be winched forward by a winch attached to a track driven ramp. As the individual interconnected units of the beltway are pulled from the roadway structure, they are skidded across the mine floor towards the track driven ramp. Thereafter, the cylinders are retracted and the roadway is then rollably winched forward on the beltway so that the entire system is in position to receive and convey the mined material as it is discharged from the mobile conveyor that is supported thereon. Additional belt structure must also be added to the rear of the beltway so that the beltway can continue to discharge the mined material onto the main belt.
The Moore et al. system does enable the elevated roadway and accompanying beltway to be extended without the need for additional auxiliary equipment; however, that system has a number of disadvantages. In particular, because the Moore system moves the elevated roadway and beltway relative to one another, the elevated roadway must comprise a separate independent structure that is capable of supporting the mobile conveying apparatus thereon. As such, the elevated roadway must be constructed with cross braces that interconnect and support the side portions of the elevated roadway. Those cross braces, however, extend across the opening above the beltway into which the mobile conveyor discharges. The braces, therefore, are often contacted by the mined material as it is discharged from the mobile conveyor. At times, due to its contact with the cross braces, pieces of the mined material are errantly thrown from the beltway structure. Such aberrantly discharged material creates a potentially hazardous condition for personnel working in the immediate area of the conveying system. Also, due to the relative proximity of the cross braces and the beltway, it is possible for larger pieces of mined material to become jammed between the cross braces and the beltway and thereby damage the belt or conveyor structure.
Also, because the elevated roadway and the beltway of Moore et al. are two independent structures that must be capable of supporting each other, in addition to supporting the mobile conveyor, they must be constructed from heavy duty structural members. Such structural members are not only expensive, but they also add to the overall weight of the system thereby making the system more difficult to move and transport within the confines of a mine. Moreover, an expensive heavy duty track mounted tail piece must be used to advance the beltway and roadway forward. Such tail piece must be equipped with heavy duty rams that can be driven into the mine roof to solidly anchor the tail piece in position so that it will remain stationary as the heavy beltway and roadway are winched forward.
Also, a typical mine floor may contain depressions, cavities, holes, etc. and, thus, is usually not perfectly level. As discussed above, the Moore system has a plurality of lift cylinders attached thereto for engaging the mine floor and lifting the beltway therefrom. If the portion of the mine floor under which one or more of the cylinders is situated is irregular or has a cavity or depression therein, the cylinder may not, when fully extended, contact the bottom thereof thereby creating an unstable structure upon which the beltway is to be advanced.
Moreover, advancement of the Moore system is a two step process. First, the beltway must be winched forward by the tailpiece. After the beltway has been advanced to the desired position, the winch must be disconnected from the beltway and attached to the roadway so that the roadway can be winched forward on the beltway. Such connection and disconnection of the winch and the separate advancement of the beltway and the roadway lengthen the amount of time that the mining process must be interrupted while the conveyor is advanced.
Thus, there is a need for an advanceable conveying system for use in connection with mobile conveying apparatus that does not include structure that will interfere with and divert material therefrom as it is being received from the mobile conveyor.
There is a further need for an advanceable conveying system that can be constructed from relatively lightweight materials so that heavy duty and expensive equipment is not required to transport the components thereof and advance the system forward.
There is yet another need for an advanceable conveying system that can be safely used on irregular support surfaces such mine floors.
There is still another need for an advanceable conveying system that can be advanced with a minimal amount of interruption to the mining process.